Ink Splitting Correction via Camera Imaging

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing inline measurement methods in printing devices face challenges in accurately correcting measurement errors caused by surface effects due to ink splitting, leading to significant differences between inline and external measurements, which complicates process interpretation and control.

Innovation Solution

An image-based correction method using a camera to identify and exclude bright pixels with surface effects from measurement calculations, allowing for quantitative determination and correction of these effects, effectively mimicking a virtual polarization filter without the drawbacks of traditional polarizing filters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If polarization filters are used to eliminate surface effects, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improvemeasurement precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses a camera to capture an optical image of the printed sheet, creating a visual copy of the surface effects. This image copy is then processed to identify and quantify surface effects, replacing the need for complex polarization filter hardware while achieving similar measurement correction goals

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent replaces the mechanical/optical polarization filter system with an imaging-based detection system. Instead of using physical polarizing filters to block surface reflections, the system uses a camera to capture and digitally process the surface appearance, substituting mechanical optical components with electronic imaging and image processing

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If polarization filters are used to eliminate surface effects, then measurement precision is improved, but installation space requirements increase

Engineering Contradiction:
Improvemeasurement precisionVSAvoidinstallation space
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The camera captures a two-dimensional image copy of the printed sheet surface, allowing surface effect analysis without requiring additional optical path space. The image processing occurs in digital space rather than requiring physical space for additional optical components

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The imaging system requires minimal installation space compared to polarization filter arrangements, as the correction is achieved through software processing of captured images rather than additional optical hardware in the measurement path

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If polarization filters are used to eliminate surface effects, then measurement precision is improved, but optical imaging quality deteriorates

Engineering Contradiction:
Improvemeasurement precisionVSAvoidoptical imaging quality
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The camera creates a complete optical image copy of the printed sheet, preserving all optical information including color and surface characteristics. The surface effect correction is achieved by analyzing this complete image copy rather than filtering the original optical path, maintaining full imaging quality

Inventive Principle:
Principle #26Copying

4Device complexity

If mathematical correction methods are used for non-imaging measurement, then device complexity is reduced, but measurement precision deteriorates due to strong surface effects

Engineering Contradiction:
Improvedevice complexityVSAvoidmeasurement precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent uses an imaging system to create a visual copy of the surface effects, enabling quantitative analysis and correction. This image-based approach provides more precise surface effect characterization than non-imaging methods, allowing for better correction accuracy while maintaining relatively simple device complexity

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent changes the measurement parameter from direct reflectance measurement to image intensity analysis. By capturing the surface appearance as an image and analyzing pixel brightness values, the system can identify and correct surface effects more accurately than traditional non-imaging methods

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach minimizes differences between inline and external measurements, enabling precise control of the printing process by accurately accounting for surface effects, improving measurement accuracy and reducing fluctuations.

Implementation Method 1

Image data obtained in this way from a camera which is attached in such a way that it can image the printed sheet

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP1958775B1Ink splitting correction method
Publication Date: 2014.08.06 X RITE EUROPE GMBH
  • EP1958775B1 patent drawingFigure 1~3
  • EP1958775B1 patent drawingFigure 4

AI summary

In a method for correcting the measurement error caused by color-splitting-related surface effects during the color measurement of a printed sheet on a running printing device, the printed sheet is scanned point by point using a radioelectric sensor, and color and/or density measurement values ​​(3) are generated from the scanning signals (1) of the scanning points. Those scanning points that exhibit a brightness exceeding a limit value (IG) are identified, and the measurement values ​​are corrected based on these identified scanning points. Specifically, the scanning signals of the identified scanning points are not taken into account when generating the color and/or density measurement values.